In a dialogue system, there is processing of assigning an intention tag representing the utterance intention of a user to a spoken sentence representing the contents of an utterance of the user. This processing generally uses a method in which a worker sees the spoken sentence and selects an intention tag considered to represent a correct intention from an intention tag candidate group. At this time, there exist, for example, a method of presenting all candidates and causing the worker to select an intention tag and a method of presenting intention tags after narrowing down them to a smaller number of more probable candidates and causing the worker to select an intention tag.
In the method of presenting all intention tag candidates, however, if the number of candidates is as large as several tens or several hundreds, it is difficult to understand the meanings of all the candidates and assign an intention tag. Additionally, if the number of candidates is large, but the work needs to be done in a short time, the accuracy of intention tag assignment processing lowers because it is hard to sufficiently understand the meanings of the candidates.
In the method of narrowing down candidates to a group of a smaller number of candidates, a correct candidate may be absent in the narrowed candidate group. In this case, a correct intention tag cannot be assigned.